Browsing by Author "CHANG, DC"

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ENHANCEMENT OF BAND-EDGE LUMINESCENCE IN HYDROGENATED STRAINED SI(0.84)GE(0.16)/SI QUANTUM-WELLS BY PHOTOCHEMICAL VAPOR-DEPOSITION
(1993-12-01)
PAN, SC
;
CHEN, YF
;
CHANG, DC
;
CHANG, CY
;
WANG, PJ
Well-resolved band-edge luminescence spectra are reported for strained Si0.84Ge0.16/Si quantum wells grown by ultrahigh-vacuum chemical-vapor-deposition at 550-degrees-C. Phonon assisted transitions are also observed and the phonon structure of the spectrum is resolved. Blue shifting of the peak emission with decreasing well width is found in good agreement with theoretical calculations. The effects of hydrogenation using photochemical vapor deposition system are studied and an enhancement of the band edge luminescence intensity by a factor of three accompanied with a decrease in the intensity of the peaks coming from lattice defects is observed after hydrogenation. These results indicate that photochemical vapor deposition system is a useful tool for injecting atomic hydrogen into Si1-xGex/Si quantum wells and to enhance the band edge luminescence as well as to passivate the activity of the defects.
OBSERVATION OF QUANTUM CONFINEMENT EFFECTS IN STRAINED SI0.84GE0.16/SI QUANTUM-WELLS AT ROOM-TEMPERATURE
(1993-05-24)
CHEN, YF
;
DAI, YT
;
CHOU, HP
;
CHANG, DC
;
CHANG, CY
We report the first study of quantum confinement shifts of energy gap in strained Si0.84Ge0.16/Si quantum wells at room temperature by photothermal deflection spectroscopy (PDS) technique. The experimental results obtained from the amplitude and phase of the PDS signal are in good agreement with quantum well subband calculation.
SUPERIOR DAMAGE-IMMUNITY OF THIN OXIDES THERMALLY GROWN ON REACTIVE-ION-ETCHED SILICON SURFACE IN N2O AMBIENT
(1994-05-01)
UENG, SY
;
CHAO, TS
;
WANG, PJ
;
CHEN, WH
;
CHANG, DC
Thin oxides thermally grown on reactive-ion-etched silicon surfaces in N2O ambient have been studied. As compared with pure oxides grown on the etched silicon in dry oxygen, N2O-grown oxides exhibit significantly stronger immunity to the RIE-induced damages. A great improvement in both time-zero-dielectric-breakdown (TZDB) and time-dependent-breakdown (TDDB) characteristics is observed for the N2O-grown oxides on RIE-treated silicon surfaces. Accelerated tests have shown that the N2O oxide grown on the RIE silicon surface can achieve a lifetime longer than the pure oxide grown on the correspondingly etched silicon surface with a factor over 10(8).
THE LONG-TERM RELAXATION AND BUILDUP TRANSIENT OF PHOTOCONDUCTIVITY IN SI1-XGEX/SI QUANTUM-WELLS
(1995-06-05)
CHU, LH
;
CHEN, YF
;
CHANG, DC
;
CHANG, CY
;
電子工程學系及電子研究所
The long-term relaxation and build-up transient of photoconductivity has been observed in Si1-xGex/Si quantum wells. The long-term relaxation behaviour pelt) of photoconductivity can be described by a stretched-exponential function, I-pc(t) = I-pc(0) exp[-(t/tau)(beta)] (0